With the improvement of people's life quality, camping, self-driving travel and other outdoor leisure activities are involved in people's life. Usually, people sleep on a mattress or in a sleeping bag in a camping. As the ground is hard and unsmooth, it sleeps uncomfortable. In addition, the ground moisture is heavy, making people easy to catch cold and feel backache, particularly to people with bad cervical and lumber vertebra. If it rains at midnight, people have nowhere to hide.
Therefore, there is a spring bed convenient to carry. The spring bed can be unfolded when unused and be put to the trunk. However, the spring beds collapse after long time's use, making it uncomfortable. The unfolded spring bed is shortened but still has a long width, still occupying large space that it can not be put in a trunk, making it inconvenient to carry.